Scientific competence during medical education - insights from a cross-sectional study at a German Medical School.

BACKGROUND: Medical knowledge regarding the pathophysiology, diagnosis and treatment of diseases is constantly evolving. To effectively incorporate these findings into professional practice, it is crucial that scientific competencies are a central component of medical education. This study seeks to analyse the current state of scientific education and students' desires for integration into the curriculum. METHODS: From October to December 2022, a survey was distributed at the Medical Faculty Dresden to all medical students from the 1st to 5th academic year (AY). The survey investigates current expectations of applying scientific competencies later in professional life, and the students were asked to self-assess various scientific skills and in relation to the National Competence Based Catalogue of Learning Objectives for Undergraduate Medical Education. The self-assessments were objectified through a competence test with ten multiple-choice questions. The desire for curricular teaching was inquired. RESULTS: 860 students completed the survey. This corresponds to a response rate of 64%. In the 5th AY, approximately 80% of the participants stated that they expected to work with scientific literature on a daily to monthly basis in future professional life and to communicate corresponding scientific findings to patients. Only 30-40% of the 5th AY rate their scientific competencies as sufficient to do this appropriately. This corresponds with the self-assessed competencies that only slightly increased over the 5 AYs from 14.1 ± 11.7 to 21.3 ± 13.8 points (max. 52) and is also reflected in the competence test (1st AY 3.6 ± 1.75 vs. 5th AY 5.5 ± 1.68, max. 10 points). Half of the students in the 4th and 5th AYs were dissatisfied with the current teaching of scientific skills. The majority preferred the implementation of a science curriculum (56%), preferably as seminars dealing with topics such as literature research, analysis, and science communication. CONCLUSIONS: The results show discrepancies between expectations of using scientific knowledge in everyday professional life, self-rated and objectively recorded competencies, and the current state of curricular teaching of scientific competencies. There is a strong need for adequate practical training, particularly in critical analyses of scientific literature, which enables the communication of scientific knowledge to patients.

Efficacy and safety of Dexrazoxane (DRZ) in sarcoma patients receiving high cumulative doses of anthracycline therapy - a retrospective study including 32 patients.

BACKGROUND: Anthracyclines, as the most effective therapy, are the cornerstone of advanced stage sarcoma treatment. However, anthracyclines can also contribute to myocardial dysfunction and congestive heart failure, ultimately limiting the therapeutic potential of the drug. Coadministration of Dexrazoxane has been shown to effectively reduce cardiotoxicity, however primarily in patients suffering in diseases other than sarcoma. METHODS: The aim of this retrospective analysis was to evaluate safety and efficacy of chemotherapy with high cumulative doses of anthracyclines in combination with Dexrazoxane. The medical charts of 32 patients treated in four institutions were analyzed. Reasons for coadministration were rechallenge, reaching the cumulative anthracycline dose and preexisting heart failure. RESULTS: The median age was 54 years [18-68 years]. The median cumulative anthracycline dose before adding DRZ was 450 mg/m(2) and after administration of last anthracycline containing therapy 750 mg/m(2). Either during treatment or follow up, 2/27 patients (7 %) without preexisting major cardiac findings developed anthracycline-induced cardiotoxicity. The median overall survival (OS) from start of the first anthracycline containing chemotherapy was 46 months and 17 months from the initial coadministration of DRZ. At rechallenge, the median progression free survival (PFS) with DRZ was 7 months. In continuous therapy, the median PFS was 13 months from beginning of chemotherapy and 9 months from the addition of DRZ. CONCLUSION: Chemotherapy with high cumulative doses of anthracyclines in addition with DRZ demonstrated a remarkable OS in these advanced disease patients. Cardiac side-effects due to high cumulative doses of anthracyclines requiring discontinuation of anthracycline treatment were rare. A PFS of 9 months from the beginning of the coadministration of DRZ indicates that continuing anthracycline therapy beyond established cumulative doses is a promising therapeutic option.

Impact of long-term exposure to the tyrosine kinase inhibitor imatinib on the skeleton of growing rats.

The tyrosine kinase (TK) inhibitor imatinib provides a highly effective therapy for chronic myeloid leukemia (CML) via inhibition of the oncogenic TK BCR-ABL1. However, off-target TKs like platelet-derived growth factor receptors (PDGF-R) and colony-stimulating factor-1 receptor (c-fms), involved in bone remodeling, are also inhibited. Thus, pediatric patients with CML on imatinib exhibit altered bone metabolism, leading to linear growth failure. As TKI treatment might be necessary for a lifetime, long-term effects exerted on bone in children are of major concern. Therefore, we studied the skeletal long-term effects of continuous and intermittent imatinib exposure in a juvenile rat model. Four-weeks-old male Wistar rats were chronically exposed to imatinib via drinking water over a period of 10 weeks. Animals were exposed to a standard and high imatinib dosage continuously and to the high imatinib dose intermittently. Bone mass and strength were assessed using pQCT, micro-computed tomography (µCT), and biomechanical testing at the prepubertal, pubertal, and postpubertal age. Bone length and vertebral height as well as biochemical markers of bone turnover were analyzed. Femoral and tibial bone length were dose-dependently reduced by up to 24% (p<0.0001), femoral and tibial trabecular bone mass density (BMD) were reduced by up to 25% (p<0.01), and femoral breaking strength was lowered by up to 20% (p<0.05). Intermittent exposure mitigated these skeletal effects. Long-term exposure resulted in reduced vertebral height by 15% and lower trabecular BMD by 5%. Skeletal changes were associated with suppressed serum osteocalcin (p<0.01) and non-significantly elevated serum CTX-I and PINP levels. In conclusion, imatinib mainly impaired longitudinal growth of long bones rather than the vertebrae of growing rats. Interestingly, intermittent imatinib exposure has less skeletal side effects, which may be beneficial in pediatric patients taking imatinib.

High-throughput monitoring of integration site clonality in preclinical and clinical gene therapy studies.

Gene transfer to hematopoietic stem cells with integrating vectors not only allows sustained correction of monogenic diseases but also tracking of individual clones in vivo. Quantitative real-time PCR (qPCR) has been shown to be an accurate method to quantify individual stem cell clones, yet due to frequently limited amounts of target material (especially in clinical studies), it is not useful for large-scale analyses. To explore whether vector integration site (IS) recovery techniques may be suitable to describe clonal contributions if combined with next-generation sequencing techniques, we designed artificial ISs of different sizes which were mixed to simulate defined clonal situations in clinical settings. We subjected all mixes to either linear amplification-mediated PCR (LAM-PCR) or nonrestrictive LAM-PCR (nrLAM-PCR), both combined with 454 sequencing. We showed that nrLAM-PCR/454-detected clonality allows estimating qPCR-detected clonality in vitro. We then followed the kinetics of two clones detected in a patient enrolled in a clinical gene therapy trial using both, nrLAM-PCR/454 and qPCR and also saw nrLAM-PCR/454 to correlate to qPCR-measured clonal contributions. The method presented here displays a feasible high-throughput strategy to monitor clonality in clinical gene therapy trials is at hand.

Cross-sectional study on the prevalence and risk indicators of peri-implant diseases.

PURPOSE: To evaluate the prevalence of peri-implant diseases in a university patient sample and to analyse possible risk variables associated with their occurrence. MATERIALS AND METHODS: One hundred and eighty-six patients with 597 implants were examined clinically and radiographically. The mean period of function was 5.5 years (range 1 to 16.5 years). A subgroup analysis was performed for implants with a minimum function time of 5 years. Outcome measures were implant failures, prevalence and risk indicators of peri-implant diseases. In order to identify statistically significant risk indicators of peri-implant mucositis and peri-implantitis multi-level logistic regression models were constructed. RESULTS: The prevalence of peri-implantitis and peri-implant mucositis on patient levels were 12.9% (13.3% for ≥ 5 years) and 64.5% (64.4% for ≥ 5 years), respectively. Multi-level analysis showed that a high plaque score (OR = 1.365; 95% CI: 1.18 to 1.57, P < 0.001) was a risk indicator for periimplant mucositis, while augmentation of the hard or soft tissue at implant sites had a protective effect (OR = 0.878 95% CI: 0.79 to 0.97, P = 0.01). It was also shown that the odds ratio for having peri-implant mucositis increased with the increase of plaque score in a dose-dependent manner. With respect to peri-implantitis, loss of the last tooth due to periodontitis (OR = 1.063; 95% CI: 1.00 to 1.12, P = 0.03) and location of the implants in the maxilla (OR = 1.052, 95% CI: 1.00 to 1.09, P = 0.02) were identified as statistically significant risk indicators. CONCLUSIONS: Within the limitations of this study, the history of periodontal disease was the most significant risk indicator for peri-implantitis and the level of oral hygiene was significantly associated with peri-implant mucositis.

Gemcitabine and docetaxel for epithelioid sarcoma: results from a retrospective, multi-institutional analysis.

OBJECTIVE: Epithelioid sarcoma (ES) presents unique clinical features in comparison to other sarcoma subtypes. Data regarding the benefits of chemotherapy are very limited. Combination regimens using gemcitabine and docetaxel (Gem/Doce) have proven to be effective, especially in uterine and nonuterine leiomyosarcoma. Yet, there is no available data on the efficacy of Gem/Doce in ES. METHODS: A retrospective analysis of the three participating institutions was performed. Twenty-eight patients with an ES diagnosis presented at one of the participating institutions between 1989 and 2012. Of this group, 17 patients received chemotherapy. RESULTS: Patients' median overall survival (OS) after the beginning of palliative chemotherapy was 21 months, and the 1-year OS was 87%. Twelve patients received Gem/Doce with a clinical benefit rate of 83%. The median progression-free survival (PFS) was 8 months for all patients receiving Gem/Doce. The best response was complete remission in 1 patient and partial remission in 6 patients. All 6 patients receiving Gem/Doce as a first-line treatment showed measurable responses with a median PFS of 9 months. CONCLUSIONS: In this retrospective study, Gem/Doce was an effective chemotherapeutic regimen for ES. Prospective studies are needed to better assess the effects of this combination drug therapy.

Multiplexing clonality: combining RGB marking and genetic barcoding.

RGB marking and DNA barcoding are two cutting-edge technologies in the field of clonal cell marking. To combine the virtues of both approaches, we equipped LeGO vectors encoding red, green or blue fluorescent proteins with complex DNA barcodes carrying color-specific signatures. For these vectors, we generated highly complex plasmid libraries that were used for the production of barcoded lentiviral vector particles. In proof-of-principle experiments, we used barcoded vectors for RGB marking of cell lines and primary murine hepatocytes. We applied single-cell polymerase chain reaction to decipher barcode signatures of individual RGB-marked cells expressing defined color hues. This enabled us to prove clonal identity of cells with one and the same RGB color. Also, we made use of barcoded vectors to investigate clonal development of leukemia induced by ectopic oncogene expression in murine hematopoietic cells. In conclusion, by combining RGB marking and DNA barcoding, we have established a novel technique for the unambiguous genetic marking of individual cells in the context of normal regeneration as well as malignant outgrowth. Moreover, the introduction of color-specific signatures in barcodes will facilitate studies on the impact of different variables (e.g. vector type, transgenes, culture conditions) in the context of competitive repopulation studies.

Comparative clonal analysis of reconstitution kinetics after transplantation of hematopoietic stem cells gene marked with a lentiviral SIN or a γ-retroviral LTR vector.

Retroviral gene marking has been used successfully in preclinical and clinical transplantation settings. Highly sensitive techniques for vector insertion-site determination, such as linear amplification-mediated polymerase chain reaction (LAM-PCR) in conjunction with next-generation sequencing, have been introduced to assess the composition of gene-marked hematopoiesis at a single-cell level. Here we used these novel techniques for directly comparing clonal reconstitution kinetics in mice transplanted with bone-marrow-derived stem cells genetically marked with either a standard, spleen focus-forming virus long terminal repeat (LTR)-driven γ-retroviral, or a lentiviral self-inactivating vector containing an identical but internal spleen focus-forming virus-derived enhancer/promoter. We observed that the use of the lentiviral self-inactivating vector for gene marking was associated with a broader repertoire of differently marked hematopoietic clones. More importantly, we found a significantly higher probability of insertions in growth-promoting, clonal-dominance-associated genes in the spleen focus-forming virus LTR-driven γ-retroviral vector at later time points of analysis. Based on our data, we suggest that the combined use of LAM-PCR and next-generation sequencing represents a potent tool for the analysis of clonal reconstitution kinetics in the context of gene marking with integrated vectors. At the same time, our findings prove that the use of multiple restriction enzymes for LAM-PCR is indispensable to detect most or ideally all individual stem cell clones contributing to hematopoiesis. We have also found that techniques such as quantitative PCR can be helpful to retrospectively analyze reconstitution kinetics for individual hematopoietic stem cell clones. Finally, our results confirm the notion that marking with lentiviral self-inactivating vectors is associated with a lower risk of genotoxicity as compared with γ-retroviral LTR vectors.

Mathematical modeling of oncogenesis control in mature T-cell populations.

T-cell receptor (TCR) polyclonal mature T cells are surprisingly resistant to oncogenic transformation after retroviral insertion of T-cell oncogenes. In a mouse model, it has been shown that mature T-cell lymphoma/leukemia (MTCLL) is not induced upon transplantation of mature, TCR polyclonal wild-type (WT) T cells, transduced with gammaretroviral vectors encoding potent T-cell oncogenes, into RAG1-deficient recipients. However, further studies demonstrated that quasi-monoclonal T cells treated with the same protocol readily induced MTCLL in the recipient mice. It has been hypothesized that in the TCR polyclonal situation, outgrowth of preleukemic cells and subsequent conversion to overt malignancy is suppressed through regulation of clonal abundances on a per-clone basis due to interactions between TCRs and self-peptide-MHC-complexes (spMHCs), while these mechanisms fail in the quasi-monoclonal situation. To quantitatively study this hypothesis, we applied a mathematical modeling approach. In particular, we developed a novel ordinary differential equation model of T-cell homeostasis, in which T-cell fate depends on spMHC-TCR-interaction-triggered stimulatory signals from antigen-presenting cells (APCs). Based on our mathematical modeling approach, we identified parameter configurations of our model, which consistently explain the observed phenomena. Our results suggest that the preleukemic cells are less competent than healthy competitor cells in acquiring survival stimuli from APCs, but that proliferation of these preleukemic cells is less dependent on survival stimuli from APCs. These predictions now call for experimental validation.